BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Kalmia angustifolia | Sheep-Laurel 



GENERAL BOTANICAL CHARACTERISTICS : 
Sheep-laurel is a small, branchy, evergreen shrub which reaches 1 to 3
feet (30-90 cm) in height.  It has pink, showy, five-part flowers on
stalked clusters.  The fruit is a small capsule containing many seeds.
Capsules may persist on the branches for several years [4,36].

Sheep-laurel forms a well-developed and closely interlacing network of
rhizomes.  The root system consists of a taproot which may extend to a
depth of 3 feet (1 m) [43].  It also has fine roots nearer to the soil
surface [6].  Fine root depths vary from 3.5 inches (9 cm) in mineral
soil to 12 inches (31 cm) in bogs [14,39].


RAUNKIAER LIFE FORM : 
   Phanerophyte


REGENERATION PROCESSES : 
Reproduction is primarily vegetative.  Sheep-laurel plants are clonal
and expand laterally.  Sprouts grow from dormant buds on rhizomes.  Very
little is known about sexual reproduction and seedling establishment.
Individual stems produce an estimated 7,100 seeds per year.  Clones are
self-compatible, but seedlings from selfing are less vigorous than
seedlings from crossing [43].


SITE CHARACTERISTICS : 
Sheep-laurel grows on a variety of sites ranging from wet sphagnum bogs
to dry jack pine forests.  It is frequently found on sites that are very
dry during the summer but saturated or flooded during the spring [34].
On peatland, it grows under both oligotrophic and ombrotrophic
conditions [3,8].  In the Northeast, sheep-laurel grows in moist conifer
woods, pastures, barrens, roadsides, and open thickets [34].

Sheep-laurel typically grows on podzols which have developed under a
cold to temperate climate on acidic parent material [43].  On peatland
it grows on well-drained peat and peaty podzols.  On forested sites
sheep-laurel grows on dry, acid, run-out soils; rocky, gravelly soils;
sandy loams; and iron-rich, lithosolic, or Ortstein podzols [7,34,36].
Its western range may be limited by high soil pH and lack of moisture
[43].

On peatlands in Newfoundland, sheep-laurel grows independent of the
mineral soil, taking all of its nutrients from the organic layer.  On
forested sites it roots in mineral soil [6].

Sheep-laurel grows under a climate regime that is cold and wet for much
of the year.  Minimum temperatures at the northern limits of its range
are -40 degrees Fahrenheit (-40 deg C) [43].


SUCCESSIONAL STATUS : 
Obligate Initial Community Species

Sheep-laurel is somewhat shade intolerant.  Under low light conditions
it persists but does not grow appreciably.  Overstory removal and
increased light trigger release, causing sheep-laurel cover to quickly
increase [3].  It is considered early successional in the bog formation
sequence, although it may become dominant and arrest succession
following bog disturbance by fire or drainage [6].  On frequently
disturbed forest sites, most logging practices favor sheep-laurel
establishment.  Clones may expand and persist for several decades,
reducing tree establishment and creating heaths or "Kalmia barrens"
[5,6,32].  On undisturbed sites sheep-laurel is replaced by trees such
as balsam fir and black spruce [5].


SEASONAL DEVELOPMENT : 
Sheep-laurel flowers during June and early July.  Its fruit ripens
between late July and mid-September [23,36,43].  The seeds disperse in
early October.  New shoot growth begins during late May and early June
[43].

Related categories for Species: Kalmia angustifolia | Sheep-Laurel